The optical design and glass coating have raised the level of the teleconverter. In addition, the redesign of the upgraded electronic aspect make the auto-focusing function of teleconverter able to adapt to more lens, such as the EF70-200MM F/2.8 L IS II, the EF70-200MM F/2.8 L IS II USM and most of the lens can achieve automatic focusing

NOTE: 1, The shooting environment, resolution and the brightness should be ideal.2, The AF Point should be adopted the free selecting focus mode.3, The Canon cameras outside the list have not been tested. In generally, if the camera focus system is advanced, it can realize automatic focus.4, When Teleconverter EF 2X is attached,the lens maximum aperture will be smaller by 2 stop.In the above two case, the camera will compensate the exposure automatically.